Usefulness of tissue Doppler-derived atrial electromechanical delay for identifying patients with paroxysmal atrial fibrillation.

Background: Tissue Doppler imaging (TDI)-derived atrial electromechanical delay (AEMD) has been reported to be useful for detecting paroxysmal atrial fibrillation (PAF). However, its usefulness remains unknown when analyzed along with patients seemingly at high-risk for AF as controls. From this standpoint, we investigated whether AEMD would be of use for identifying patients with PAF.
Methods: We retrospectively analyzed TDI recordings to obtain AEMD in 63 PAF patients. Thirty-three patients with multiple cardiovascular risk factors (MRFs) but without history of AF and 50 healthy individuals served as disease and healthy controls, respectively. AEMD was defined as the time-interval between the electrocardiogram P-wave and the beginning of the spectral TDI-derived A' for the septal (septal EMD) and lateral (lateral EMD) sides of the mitral annulus.
Results: There was no significant difference in the left atrial volume index between PAF patients and disease controls (28 ± 9 mL/m ² vs. 27 ± 5 mL/m ² ). PAF patients had longer AEMD, particularly for the lateral EMD (75 ± 23 ms), compared with disease (62 ± 22 ms, P = 0.009) and healthy (54 ± 24 ms, P < 0.001) controls. Multivariate logistic regression analysis revealed that the lateral EMD (OR 1.25, 95%CI 1.03-1.52, P = 0.023), along with the left atrial volume index (OR 2.25, 95%CI 1.44-3.51, P < 0.001), was one of the significant independent associates of identifying PAF patients.
Conclusions: This cross-sectional study indicates that even analyzed together with MRFs patients, AEMD remains useful for identifying patients at risk for AF. Our results need to be confirmed by a large-scale prospective study.